1. Technical Field
The present invention relates to a cable connector for connecting cable conductors of a flat cable to wire conductors of external wires, and more specifically to a cable connector suitable for use with a brushless electric signal transmitting apparatus mounted in a steering column of an automotive vehicle, for instance to transmit a number of electric signals from a rotating steering handle shaft to a fixed steering column through the flat cable.
2. Description of the Related Art
Recently, with the advance of an electric control system for au automotive vehicle, a number of switches are required to be arranged on a steering handle (steering wheel) of an automotive vehicle for activating various electric control circuits, so that it is necessary to electrically connect these rotating switches to control circuits by wires through a rotary steering handle and a fixed steering column. Here, since the steering handle of the automotive vehicle is fixed to a rotary handle shaft rotatable both clockwise and counterclockwise by a few turns relative to the fixed steering column, a brushless electric signal transmitting apparatus is used to transmit a plurality of electric signals between the rotary handle shaft and the fixed steering column through a flexible flat cable (referred to as a flat cable, hereinafter) having a plurality of conductive cable wires therein. In this electric signal transmitting apparatus, the flat cable is disposed in an annular space formed between a rotary body fixed to the handle shaft side and a housing fixed to the steering column side under such a condition that the flat cable is wound into a vortex state or into a reversed vortex state (being returned midway of the flat cable).
In the above-mentioned brushless electric signal transmitting apparatus, it is necessary to connect wires extending from the switches arranged on the steering handle to cable conductors of an inner end of the flat cable and further to connect cable conductors of an outer end of the flat cable to wires extending to the control circuits, by use of appropriate flat cable connectors, respectively.
FIGS. 1(A) and 1(B) show a conventional cable connector 610 for connecting cable conductors 600A of a flat cable 600 to wire conductors 500A of the wires 500, which is disclosed in Japanese Published Unexamined (Kokai) Application No. 63-58486. In more detail, the cable connector 610 (used as both the inner and outer flat cable connectors) is composed of a connector body 610A and a cover (not shown). In this cable connector 610, an L-shaped internal recess 610B is formed in the connector body 610A,.
In connection by use of the cable connector 610, the wire conductors 500A of the wires 500 are first soldered to conductors 600A of the flat cable 600, and then bent at right angles along the L-shaped recess 610B of the connector body 610A to put the soldered wires 500 to the recess 610B of the connector body 610A, respectively. After that, the connector body 610A is covered with the cover (not shown).
However, the conventional cable connector 610 for connecting the wires 500 with the flat cable 600 involves the following problems:
(1) A jig is necessary to locate or temporarily fix the wire conductors 500A of the wires 500 relative to the conductors 600A of the flat cable 600, so that the conductor connecting work is complicated and needs a number of steps. PA1 (2) After the wires 500 have been connected to the flat cable 600, since the connected wires 500 are bent along the recess 610B of the connector body 610A and further a cover must be attached to the connector body 610A, an internal stress is inevitably generated at the conductors 600A of the flat cable 600, so that there exists a problem in that the conductors 600A of the flat cable 600 are broken off at the worst. PA1 (3) Even after the wires 500 have been soldered to the flat cable 600, when an tension is applied to the wires 500, since the applied tension cannot be received by the connector body 610A, a problem arises in that the conductors 600A of the flat cable 600 are cracked as shown by Z in FIG. 1(B) or broken off at the worst.